The present invention relates to a method and apparatus for recovering silver from waste photographic processing solutions by reducing silver ions and allowing them to be precipitated as silver grains.
Waste photographic processing solutions such as bleach-fixing baths and fixing baths that have been used to process photosensitive materials contain silver in high concentrations. High silver contents have the great potential to cause to environmental pollutions but on the other hand they are valuable resources. Thus, it is a recent practice in the art to recover silver from waste photographic processing solutions. There are various ways in which silver can be recovered from waste photographic processing solutions and they may be roughly classified as the following three types: